mirror of
https://github.com/bolero-MURAKAMI/Sprout.git
synced 2024-11-14 10:39:05 +00:00
364 lines
12 KiB
C++
364 lines
12 KiB
C++
/*=============================================================================
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Copyright (c) 2011-2014 Bolero MURAKAMI
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https://github.com/bolero-MURAKAMI/Sprout
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Distributed under the Boost Software License, Version 1.0. (See accompanying
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file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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=============================================================================*/
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#ifndef SPROUT_OPTIONAL_OPTIONAL_HPP
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#define SPROUT_OPTIONAL_OPTIONAL_HPP
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#include <type_traits>
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#include <initializer_list>
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#include <sprout/config.hpp>
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#include <sprout/detail/predef.hpp>
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#include <sprout/utility/value_holder/value_holder.hpp>
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#include <sprout/utility/value_holder/get.hpp>
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#include <sprout/utility/swap.hpp>
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#include <sprout/utility/forward.hpp>
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#include <sprout/utility/move.hpp>
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#include <sprout/type_traits/std_type_traits.hpp>
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#include <sprout/type_traits/is_convert_constructible.hpp>
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#include <sprout/none.hpp>
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#include <sprout/optional/nullopt.hpp>
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#include <sprout/optional/in_place.hpp>
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#include <sprout/optional/exceptions.hpp>
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#include <sprout/assert.hpp>
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namespace sprout {
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//
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// optional
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//
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template<typename T>
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class optional {
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public:
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typedef T type;
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private:
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typedef sprout::value_holder<type> holder_type;
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public:
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typedef typename holder_type::value_type value_type;
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typedef typename holder_type::lvalue_reference lvalue_reference;
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typedef typename holder_type::rvalue_reference rvalue_reference;
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typedef typename holder_type::reference reference;
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typedef typename holder_type::const_lvalue_reference const_lvalue_reference;
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typedef typename holder_type::const_rvalue_reference const_rvalue_reference;
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typedef typename holder_type::const_reference const_reference;
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typedef typename holder_type::pointer pointer;
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typedef typename holder_type::const_pointer const_pointer;
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typedef typename holder_type::lvalue_reference_type lvalue_reference_type;
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typedef typename holder_type::rvalue_reference_type rvalue_reference_type;
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typedef typename holder_type::reference_type reference_type;
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typedef typename holder_type::reference_const_type reference_const_type;
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typedef typename holder_type::pointer_type pointer_type;
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typedef typename holder_type::pointer_const_type pointer_const_type;
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public:
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template<typename... Args>
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struct is_constructible_args
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: public sprout::is_constructible<T, Args&&...>
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{};
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public:
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static SPROUT_CONSTEXPR reference_type get(optional& t) SPROUT_NOEXCEPT {
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return sprout::get(t.val);
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}
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static SPROUT_CONSTEXPR rvalue_reference_type get(optional&& t) SPROUT_NOEXCEPT {
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return static_cast<rvalue_reference_type>(get(t));
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}
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static SPROUT_CONSTEXPR reference_const_type get(optional const& t) SPROUT_NOEXCEPT {
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return sprout::get(t.val);
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}
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static SPROUT_CONSTEXPR pointer_type get_pointer(optional& t) SPROUT_NOEXCEPT {
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return sprout::get_pointer(t.val);
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}
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static SPROUT_CONSTEXPR pointer_type get_pointer(optional&& t) SPROUT_NOEXCEPT {
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return get_pointer(t);
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}
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static SPROUT_CONSTEXPR pointer_const_type get_pointer(optional const& t) SPROUT_NOEXCEPT {
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return sprout::get_pointer(t.val);
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}
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static SPROUT_CONSTEXPR reference_type get_value_or(optional& t, reference_type v) SPROUT_NOEXCEPT {
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return t.is_initialized() ? sprout::get(t.val)
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: v
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;
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}
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static SPROUT_CONSTEXPR rvalue_reference_type get_value_or(optional&& t, rvalue_reference_type v) SPROUT_NOEXCEPT {
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return static_cast<rvalue_reference_type>(get_value_or(t, v));
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}
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static SPROUT_CONSTEXPR reference_const_type get_value_or(optional const& t, reference_const_type v) SPROUT_NOEXCEPT {
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return t.is_initialized() ? sprout::get(t.val)
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: v
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;
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}
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private:
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bool init;
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holder_type val;
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private:
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SPROUT_CXX14_CONSTEXPR void destroy() SPROUT_NOEXCEPT {
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init = false;
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}
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public:
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// 20.6.4.1, constructors
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SPROUT_CONSTEXPR optional() SPROUT_NOEXCEPT
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: init(false)
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{}
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SPROUT_CONSTEXPR optional(sprout::nullopt_t) SPROUT_NOEXCEPT
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: init(false)
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{}
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SPROUT_CONSTEXPR optional(optional const& v)
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: init(v.init)
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, val(v.is_initialized() ? holder_type(*v) : holder_type())
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{}
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#if SPROUT_GCC_IN_RANGE((4, 8, 0), (4, 8, 2))
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optional(optional&&) = default;
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#else
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SPROUT_CONSTEXPR optional(optional&& v)
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SPROUT_NOEXCEPT_EXPR(std::is_nothrow_move_constructible<T>::value)
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: init(v.init)
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, val(v.is_initialized() ? holder_type(sprout::move(get(v))) : holder_type())
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{}
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#endif
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SPROUT_CONSTEXPR optional(T const& v)
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: init(true)
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, val(v)
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{}
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// !!! TEMP: for T const&
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// SPROUT_CONSTEXPR optional(T&& v)
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// : init(true)
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// , val(sprout::move(v))
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// {}
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template<
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typename... Args,
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typename = typename std::enable_if<is_constructible_args<Args...>::value>::type
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>
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explicit SPROUT_CONSTEXPR optional(sprout::in_place_t, Args&&... args)
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: init(true)
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, val(sprout::in_place, sprout::forward<Args>(args)...)
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{}
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template<
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typename U, typename... Args,
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typename = typename std::enable_if<is_constructible_args<std::initializer_list<U>&, Args...>::value>::type
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>
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explicit SPROUT_CONSTEXPR optional(sprout::in_place_t, std::initializer_list<U> il, Args&&... args)
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: init(true)
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, val(sprout::in_place, il, sprout::forward<Args>(args)...)
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{}
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SPROUT_CONSTEXPR optional(bool cond, T const& v)
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: init(cond)
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, val(cond ? holder_type(v) : holder_type())
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{}
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// !!! TEMP: for T const&
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// SPROUT_CONSTEXPR optional(bool cond, T&& v)
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// : init(cond)
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// , val(cond ? holder_type(sprout::move(v)) : holder_type())
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// {}
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template<typename U>
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explicit SPROUT_CONSTEXPR optional(optional<U> const& v)
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: init(v.is_initialized())
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, val(v.is_initialized() ? holder_type(*v) : holder_type())
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{}
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template<typename U>
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explicit SPROUT_CONSTEXPR optional(optional<U>&& v)
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: init(v.is_initialized())
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, val(v.is_initialized() ? holder_type(sprout::move(optional<U>::get(v))) : holder_type())
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{}
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// 20.6.4.3, assignment
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SPROUT_CXX14_CONSTEXPR optional& operator=(sprout::nullopt_t v) SPROUT_NOEXCEPT {
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assign(v);
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return *this;
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}
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SPROUT_CXX14_CONSTEXPR optional& operator=(optional const& v) {
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assign(v);
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return *this;
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}
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SPROUT_CXX14_CONSTEXPR optional& operator=(optional&& v)
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SPROUT_NOEXCEPT_EXPR(std::is_move_constructible<T>::value && std::is_move_assignable<T>::value)
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{
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assign(sprout::forward<optional>(v));
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return *this;
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}
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template<
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typename U,
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// typename = typename std::enable_if<std::is_constructible<T, U>::value && std::is_assignable<U, T>::value>::type
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typename = typename std::enable_if<std::is_constructible<T, U&&>::value>::type
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>
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SPROUT_CXX14_CONSTEXPR optional& operator=(U&& v) {
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assign(sprout::forward<U>(v));
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return *this;
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}
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template<typename U>
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SPROUT_CXX14_CONSTEXPR optional& operator=(optional<U> const& v) {
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assign(v);
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return *this;
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}
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template<typename U>
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SPROUT_CXX14_CONSTEXPR optional& operator=(optional<U>&& v) {
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assign(sprout::forward<optional<U> >(v));
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return *this;
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}
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template<
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typename... Args,
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typename = typename std::enable_if<is_constructible_args<Args...>::value>::type
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>
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SPROUT_CXX14_CONSTEXPR void emplace(Args&&... args) {
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optional temp(sprout::in_place, sprout::forward<Args>(args)...);
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temp.swap(*this);
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}
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template<
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typename U, typename... Args,
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typename = typename std::enable_if<is_constructible_args<std::initializer_list<U>&, Args...>::value>::type
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>
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SPROUT_CXX14_CONSTEXPR void emplace(std::initializer_list<U> il, Args&&... args) {
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optional temp(sprout::in_place, il, sprout::forward<Args>(args)...);
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temp.swap(*this);
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}
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SPROUT_CXX14_CONSTEXPR void assign(sprout::nullopt_t) SPROUT_NOEXCEPT {
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destroy();
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}
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SPROUT_CXX14_CONSTEXPR void assign(optional const& v) {
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optional temp(v);
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temp.swap(*this);
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}
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SPROUT_CXX14_CONSTEXPR void assign(optional&& v)
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SPROUT_NOEXCEPT_EXPR(std::is_move_constructible<T>::value && std::is_move_assignable<T>::value)
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{
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optional temp(sprout::forward<optional>(v));
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temp.swap(*this);
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}
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template<
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typename U,
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// typename = typename std::enable_if<std::is_constructible<T, U>::value && std::is_assignable<U, T>::value>::type
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typename = typename std::enable_if<std::is_constructible<T, U&&>::value>::type
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>
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SPROUT_CXX14_CONSTEXPR void assign(U&& v) {
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optional temp(sprout::forward<U>(v));
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temp.swap(*this);
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}
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template<typename U>
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SPROUT_CXX14_CONSTEXPR void assign(optional<U> const& v) {
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optional temp(v);
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temp.swap(*this);
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}
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template<typename U>
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SPROUT_CXX14_CONSTEXPR void assign(optional<U>&& v) {
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optional temp(sprout::forward<optional<U> >(v));
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temp.swap(*this);
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}
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SPROUT_CXX14_CONSTEXPR void reset() SPROUT_NOEXCEPT {
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destroy();
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}
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SPROUT_CXX14_CONSTEXPR void reset(sprout::nullopt_t v) SPROUT_NOEXCEPT {
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assign(v);
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}
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template<
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typename U,
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// typename = typename std::enable_if<std::is_constructible<T, U>::value && std::is_assignable<U, T>::value>::type
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typename = typename std::enable_if<std::is_constructible<T, U&&>::value>::type
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>
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SPROUT_CXX14_CONSTEXPR void reset(U&& v) {
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assign(sprout::forward<U>(v));
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}
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// 20.6.4.4, swap
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SPROUT_CXX14_CONSTEXPR void swap(optional& other)
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SPROUT_NOEXCEPT_EXPR(SPROUT_NOEXCEPT_EXPR(sprout::swap(val, other.val)))
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{
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sprout::swap(init, other.init);
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sprout::swap(val, other.val);
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}
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// 20.6.4.5, observers
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SPROUT_CONSTEXPR pointer_const_type operator->() const {
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return SPROUT_ASSERT(is_initialized()),
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val.get_pointer()
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;
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}
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SPROUT_CXX14_CONSTEXPR pointer_type operator->() {
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return SPROUT_ASSERT(is_initialized()),
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val.get_pointer()
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;
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}
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SPROUT_CONSTEXPR pointer_const_type get_pointer() const {
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return is_initialized() ? val.get_pointer()
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: 0
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;
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}
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SPROUT_CXX14_CONSTEXPR pointer_type get_pointer() {
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return is_initialized() ? val.get_pointer()
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: 0
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;
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}
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SPROUT_CONSTEXPR pointer_const_type get_ptr() const {
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return get_pointer();
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}
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SPROUT_CXX14_CONSTEXPR pointer_type get_ptr() {
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return get_pointer();
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}
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SPROUT_CONSTEXPR reference_const_type operator*() const {
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return (SPROUT_ASSERT(is_initialized()), true) ? val.get()
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: val.get()
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;
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}
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SPROUT_CXX14_CONSTEXPR reference_type operator*() {
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return (SPROUT_ASSERT(is_initialized()), true) ? val.get()
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: val.get()
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;
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}
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SPROUT_CONSTEXPR reference_const_type value() const {
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return get();
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}
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SPROUT_CXX14_CONSTEXPR reference_type value() {
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return get();
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}
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SPROUT_CONSTEXPR reference_const_type get() const {
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return is_initialized() ? val.get()
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: (throw sprout::bad_optional_access("optional<>: bad optional access"), val.get())
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;
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}
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SPROUT_CXX14_CONSTEXPR reference_type get() {
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return is_initialized() ? val.get()
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: (throw sprout::bad_optional_access("optional<>: bad optional access"), val.get())
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;
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}
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SPROUT_CONSTEXPR reference_const_type value_or(reference_const_type& v) const {
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return get_value_or(v);
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}
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SPROUT_CXX14_CONSTEXPR reference_type value_or(reference_type& v) {
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return get_value_or(v);
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}
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SPROUT_CONSTEXPR reference_const_type get_value_or(reference_const_type& v) const {
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return is_initialized() ? val.get()
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: v
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;
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}
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SPROUT_CXX14_CONSTEXPR reference_type get_value_or(reference_type& v) {
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return is_initialized() ? val.get()
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: v
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;
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}
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SPROUT_EXPLICIT_CONVERSION SPROUT_CONSTEXPR operator bool() const SPROUT_NOEXCEPT {
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return is_initialized();
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}
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SPROUT_CONSTEXPR bool operator!() const SPROUT_NOEXCEPT {
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return !is_initialized();
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}
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SPROUT_CONSTEXPR bool is_initialized() const SPROUT_NOEXCEPT {
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return init;
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}
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};
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//
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// swap
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//
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template<typename T>
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inline SPROUT_CXX14_CONSTEXPR void
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swap(sprout::optional<T>& lhs, sprout::optional<T>& rhs)
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SPROUT_NOEXCEPT_EXPR(SPROUT_NOEXCEPT_EXPR(lhs.swap(rhs)))
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{
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lhs.swap(rhs);
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}
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} // namespace sprout
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#endif // #ifndef SPROUT_OPTIONAL_OPTIONAL_HPP
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